/*
* tclConfig.c --
*
* This file provides the facilities which allow Tcl and other packages
* to embed configuration information into their binary libraries.
*
* Copyright (c) 2002 Andreas Kupries <[email protected]>
*
* See the file "license.terms" for information on usage and redistribution of
* this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
* RCS: @(#) $Id: tclConfig.c,v 1.19 2007/12/13 15:23:16 dgp Exp $
*/
#include "tclInt.h"
/*
* Internal structure to hold embedded configuration information.
*
* Our structure is a two-level dictionary associated with the 'interp'. The
* first level is keyed with the package name and maps to the dictionary for
* that package. The package dictionary is keyed with metadata keys and maps
* to the metadata value for that key. This is package specific. The metadata
* values are in UTF-8, converted from the external representation given to us
* by the caller.
*/
#define ASSOC_KEY "tclPackageAboutDict"
/*
* A ClientData struct for the QueryConfig command. Store the two bits
* of data we need; the package name for which we store a config dict,
* and the (Tcl_Interp *) in which it is stored.
*/
typedef struct QCCD {
Tcl_Obj *pkg;
Tcl_Interp *interp;
} QCCD;
/*
* Static functions in this file:
*/
static int QueryConfigObjCmd(ClientData clientData,
Tcl_Interp *interp, int objc,
struct Tcl_Obj *CONST *objv);
static void QueryConfigDelete(ClientData clientData);
static Tcl_Obj * GetConfigDict(Tcl_Interp *interp);
static void ConfigDictDeleteProc(ClientData clientData,
Tcl_Interp *interp);
/*
*----------------------------------------------------------------------
*
* Tcl_RegisterConfig --
*
* See TIP#59 for details on what this function does.
*
* Results:
* None.
*
* Side effects:
* Creates namespace and cfg query command in it as per TIP #59.
*
*----------------------------------------------------------------------
*/
void
Tcl_RegisterConfig(
Tcl_Interp *interp, /* Interpreter the configuration command is
* registered in. */
CONST char *pkgName, /* Name of the package registering the
* embedded configuration. ASCII, thus in
* UTF-8 too. */
Tcl_Config *configuration, /* Embedded configuration. */
CONST char *valEncoding) /* Name of the encoding used to store the
* configuration values, ASCII, thus UTF-8. */
{
Tcl_Obj *pDB, *pkgDict;
Tcl_DString cmdName;
Tcl_Config *cfg;
Tcl_Encoding venc = Tcl_GetEncoding(NULL, valEncoding);
QCCD *cdPtr = (QCCD *)ckalloc(sizeof(QCCD));
cdPtr->interp = interp;
cdPtr->pkg = Tcl_NewStringObj(pkgName, -1);
/*
* Phase I: Adding the provided information to the internal database of
* package meta data. Only if we have an ok encoding.
*
* Phase II: Create a command for querying this database, specific to the
* package registerting its configuration. This is the approved interface
* in TIP 59. In the future a more general interface should be done, as
* followup to TIP 59. Simply because our database is now general across
* packages, and not a structure tied to one package.
*
* Note, the created command will have a reference through its clientdata.
*/
Tcl_IncrRefCount(cdPtr->pkg);
/*
* For venc == NULL aka bogus encoding we skip the step setting up the
* dictionaries visible at Tcl level. I.e. they are not filled
*/
if (venc != NULL) {
/*
* Retrieve package specific configuration...
*/
pDB = GetConfigDict(interp);
if (Tcl_DictObjGet(interp, pDB, cdPtr->pkg, &pkgDict) != TCL_OK
|| (pkgDict == NULL)) {
pkgDict = Tcl_NewDictObj();
} else if (Tcl_IsShared(pkgDict)) {
pkgDict = Tcl_DuplicateObj(pkgDict);
}
/*
* Extend the package configuration...
*/
for (cfg=configuration ; cfg->key!=NULL && cfg->key[0]!='\0' ; cfg++) {
Tcl_DString conv;
CONST char *convValue =
Tcl_ExternalToUtfDString(venc, cfg->value, -1, &conv);
/*
* We know that the keys are in ASCII/UTF-8, so for them is no
* conversion required.
*/
Tcl_DictObjPut(interp, pkgDict, Tcl_NewStringObj(cfg->key, -1),
Tcl_NewStringObj(convValue, -1));
Tcl_DStringFree(&conv);
}
/*
* We're now done with the encoding, so drop it.
*/
Tcl_FreeEncoding(venc);
/*
* Write the changes back into the overall database.
*/
Tcl_DictObjPut(interp, pDB, cdPtr->pkg, pkgDict);
}
/*
* Now create the interface command for retrieval of the package
* information.
*/
Tcl_DStringInit(&cmdName);
Tcl_DStringAppend(&cmdName, "::", -1);
Tcl_DStringAppend(&cmdName, pkgName, -1);
/*
* The incomplete command name is the name of the namespace to place it
* in.
*/
if (Tcl_FindNamespace(interp, Tcl_DStringValue(&cmdName), NULL,
TCL_GLOBAL_ONLY) == NULL) {
if (Tcl_CreateNamespace(interp, Tcl_DStringValue(&cmdName),
NULL, NULL) == NULL) {
Tcl_Panic("%s.\n%s: %s",
Tcl_GetStringResult(interp), "Tcl_RegisterConfig",
"Unable to create namespace for package configuration.");
}
}
Tcl_DStringAppend(&cmdName, "::pkgconfig", -1);
if (Tcl_CreateObjCommand(interp, Tcl_DStringValue(&cmdName),
QueryConfigObjCmd, (ClientData) cdPtr, QueryConfigDelete) == NULL) {
Tcl_Panic("%s: %s", "Tcl_RegisterConfig",
"Unable to create query command for package configuration");
}
Tcl_DStringFree(&cmdName);
}
/*
*----------------------------------------------------------------------
*
* QueryConfigObjCmd --
*
* Implementation of "::<package>::pkgconfig", the command to query
* configuration information embedded into a binary library.
*
* Results:
* A standard tcl result.
*
* Side effects:
* See the manual for what this command does.
*
*----------------------------------------------------------------------
*/
static int
QueryConfigObjCmd(
ClientData clientData,
Tcl_Interp *interp,
int objc,
struct Tcl_Obj *CONST *objv)
{
QCCD *cdPtr = (QCCD *) clientData;
Tcl_Obj *pkgName = cdPtr->pkg;
Tcl_Obj *pDB, *pkgDict, *val, *listPtr;
int n, index;
static CONST char *subcmdStrings[] = {
"get", "list", NULL
};
enum subcmds {
CFG_GET, CFG_LIST
};
if ((objc < 2) || (objc > 3)) {
Tcl_WrongNumArgs(interp, 1, objv, "subcommand ?argument?");
return TCL_ERROR;
}
if (Tcl_GetIndexFromObj(interp, objv[1], subcmdStrings, "subcommand", 0,
&index) != TCL_OK) {
return TCL_ERROR;
}
pDB = GetConfigDict(interp);
if (Tcl_DictObjGet(interp, pDB, pkgName, &pkgDict) != TCL_OK
|| pkgDict == NULL) {
/*
* Maybe a Tcl_Panic is better, because the package data has to be
* present.
*/
Tcl_SetResult(interp, "package not known", TCL_STATIC);
return TCL_ERROR;
}
switch ((enum subcmds) index) {
case CFG_GET:
if (objc != 3) {
Tcl_WrongNumArgs(interp, 2, objv, "key");
return TCL_ERROR;
}
if (Tcl_DictObjGet(interp, pkgDict, objv [2], &val) != TCL_OK
|| val == NULL) {
Tcl_SetResult(interp, "key not known", TCL_STATIC);
return TCL_ERROR;
}
Tcl_SetObjResult(interp, val);
return TCL_OK;
case CFG_LIST:
if (objc != 2) {
Tcl_WrongNumArgs(interp, 2, objv, NULL);
return TCL_ERROR;
}
Tcl_DictObjSize(interp, pkgDict, &n);
listPtr = Tcl_NewListObj(n, NULL);
if (!listPtr) {
Tcl_SetResult(interp, "insufficient memory to create list",
TCL_STATIC);
return TCL_ERROR;
}
if (n) {
List *listRepPtr = (List *)
listPtr->internalRep.twoPtrValue.ptr1;
Tcl_DictSearch s;
Tcl_Obj *key, **vals;
int done, i = 0;
listRepPtr->elemCount = n;
vals = &listRepPtr->elements;
for (Tcl_DictObjFirst(interp, pkgDict, &s, &key, NULL, &done);
!done; Tcl_DictObjNext(&s, &key, NULL, &done)) {
vals[i++] = key;
Tcl_IncrRefCount(key);
}
}
Tcl_SetObjResult(interp, listPtr);
return TCL_OK;
default:
Tcl_Panic("QueryConfigObjCmd: Unknown subcommand to 'pkgconfig'. This can't happen");
break;
}
return TCL_ERROR;
}
/*
*-------------------------------------------------------------------------
*
* QueryConfigDelete --
*
* Command delete function. Cleans up after the configuration query
* command when it is deleted by the user or during finalization.
*
* Results:
* None.
*
* Side effects:
* Deallocates all non-transient memory allocated by Tcl_RegisterConfig.
*
*-------------------------------------------------------------------------
*/
static void
QueryConfigDelete(
ClientData clientData)
{
QCCD *cdPtr = (QCCD *) clientData;
Tcl_Obj *pkgName = cdPtr->pkg;
Tcl_Obj *pDB = GetConfigDict(cdPtr->interp);
Tcl_DictObjRemove(NULL, pDB, pkgName);
Tcl_DecrRefCount(pkgName);
ckfree((char *)cdPtr);
}
/*
*-------------------------------------------------------------------------
*
* GetConfigDict --
*
* Retrieve the package metadata database from the interpreter.
* Initializes it, if not present yet.
*
* Results:
* A Tcl_Obj reference
*
* Side effects:
* May allocate a Tcl_Obj.
*
*-------------------------------------------------------------------------
*/
static Tcl_Obj *
GetConfigDict(
Tcl_Interp *interp)
{
Tcl_Obj *pDB = Tcl_GetAssocData(interp, ASSOC_KEY, NULL);
if (pDB == NULL) {
pDB = Tcl_NewDictObj();
Tcl_IncrRefCount(pDB);
Tcl_SetAssocData(interp, ASSOC_KEY, ConfigDictDeleteProc, pDB);
}
return pDB;
}
/*
*----------------------------------------------------------------------
*
* ConfigDictDeleteProc --
*
* This function is associated with the "Package About dict" assoc data
* for an interpreter; it is invoked when the interpreter is deleted in
* order to free the information assoicated with any pending error
* reports.
*
* Results:
* None.
*
* Side effects:
* The package metadata database is freed.
*
*----------------------------------------------------------------------
*/
static void
ConfigDictDeleteProc(
ClientData clientData, /* Pointer to Tcl_Obj. */
Tcl_Interp *interp) /* Interpreter being deleted. */
{
Tcl_Obj *pDB = (Tcl_Obj *) clientData;
Tcl_DecrRefCount(pDB);
}
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/
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